diff options
author | Steven Rostedt <srostedt@redhat.com> | 2009-02-27 21:33:02 -0500 |
---|---|---|
committer | Steven Rostedt <srostedt@redhat.com> | 2009-02-28 02:59:43 -0500 |
commit | 6ecc2d1ca39177edb6fbdb7412948b0e9f409d02 (patch) | |
tree | 336a12a2f3db016f967717e1cb06e9171a239ce5 /kernel/trace/trace_events.c | |
parent | eb594e45f6979cd10b18d87f7b3f02119e00a108 (diff) |
tracing: add subsystem level to trace events
If a trace point header defines TRACE_SYSTEM, then it will add the
following trace points into that event system.
If include/trace/irq_event_types.h has:
#define TRACE_SYSTEM irq
at the top and
#undef TRACE_SYSTEM
at the bottom, then a directory "irq" will be created in the
/debug/tracing/events directory. Inside that directory will contain the
two trace points that are defined in include/trace/irq_event_types.h.
Only adding the above to irq and not to sched, we get:
# ls /debug/tracing/events/
irq sched_process_exit sched_signal_send sched_wakeup_new
sched_kthread_stop sched_process_fork sched_switch
sched_kthread_stop_ret sched_process_free sched_wait_task
sched_migrate_task sched_process_wait sched_wakeup
# ls /debug/tracing/events/irq
irq_handler_entry irq_handler_exit
If we add #define TRACE_SYSTEM sched to the trace/sched_event_types.h
then the rest of the trace events will be put in a sched directory
within the events directory.
I've been playing with this idea of the subsystem for a while, but
recently Tom Zanussi posted some patches to lkml that included this
method. Tom's approach was clean and got me to finally put some effort
to clean up the event trace points.
Thanks to Tom Zanussi for demonstrating how nice the subsystem
method is.
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Diffstat (limited to 'kernel/trace/trace_events.c')
-rw-r--r-- | kernel/trace/trace_events.c | 48 |
1 files changed, 48 insertions, 0 deletions
diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c index 3bcb9df93342..19332200c457 100644 --- a/kernel/trace/trace_events.c +++ b/kernel/trace/trace_events.c | |||
@@ -345,11 +345,59 @@ static struct dentry *event_trace_events_dir(void) | |||
345 | return d_events; | 345 | return d_events; |
346 | } | 346 | } |
347 | 347 | ||
348 | struct event_subsystem { | ||
349 | struct list_head list; | ||
350 | const char *name; | ||
351 | struct dentry *entry; | ||
352 | }; | ||
353 | |||
354 | static LIST_HEAD(event_subsystems); | ||
355 | |||
356 | static struct dentry * | ||
357 | event_subsystem_dir(const char *name, struct dentry *d_events) | ||
358 | { | ||
359 | struct event_subsystem *system; | ||
360 | |||
361 | /* First see if we did not already create this dir */ | ||
362 | list_for_each_entry(system, &event_subsystems, list) { | ||
363 | if (strcmp(system->name, name) == 0) | ||
364 | return system->entry; | ||
365 | } | ||
366 | |||
367 | /* need to create new entry */ | ||
368 | system = kmalloc(sizeof(*system), GFP_KERNEL); | ||
369 | if (!system) { | ||
370 | pr_warning("No memory to create event subsystem %s\n", | ||
371 | name); | ||
372 | return d_events; | ||
373 | } | ||
374 | |||
375 | system->entry = debugfs_create_dir(name, d_events); | ||
376 | if (!system->entry) { | ||
377 | pr_warning("Could not create event subsystem %s\n", | ||
378 | name); | ||
379 | kfree(system); | ||
380 | return d_events; | ||
381 | } | ||
382 | |||
383 | system->name = name; | ||
384 | list_add(&system->list, &event_subsystems); | ||
385 | |||
386 | return system->entry; | ||
387 | } | ||
388 | |||
348 | static int | 389 | static int |
349 | event_create_dir(struct ftrace_event_call *call, struct dentry *d_events) | 390 | event_create_dir(struct ftrace_event_call *call, struct dentry *d_events) |
350 | { | 391 | { |
351 | struct dentry *entry; | 392 | struct dentry *entry; |
352 | 393 | ||
394 | /* | ||
395 | * If the trace point header did not define TRACE_SYSTEM | ||
396 | * then the system would be called "TRACE_SYSTEM". | ||
397 | */ | ||
398 | if (strcmp(call->system, "TRACE_SYSTEM") != 0) | ||
399 | d_events = event_subsystem_dir(call->system, d_events); | ||
400 | |||
353 | call->dir = debugfs_create_dir(call->name, d_events); | 401 | call->dir = debugfs_create_dir(call->name, d_events); |
354 | if (!call->dir) { | 402 | if (!call->dir) { |
355 | pr_warning("Could not create debugfs " | 403 | pr_warning("Could not create debugfs " |